A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-energy exhaust gas flow. The energetic gas flow expands through the turbine section to drive the compressor and the fan section and finally exits through a thrusting nozzle.
Temperature and overall pressure ratio are factors that can limit operation and performance of a gas turbine engine. Higher pressure ratios result in higher operating temperatures in key locations of the gas turbine engine. In a mixed flow turbofan gas turbine engine the overall pressure ratio is limited by the unique match of static pressures between a bypass stream and the core engine stream exiting a low pressure turbine. Moreover, increased pressures increase temperatures beyond desirable limits and therefore also limit overall engine operation.
Accordingly, it is desirable to develop and design an engine architecture for a mixed turbofan gas turbine engine that provides for operation at higher pressure ratios while remaining within temperature and other operational limitations.